Electric-arc lamp.



No. 778,915. PATBNTED JAN. 3, 1905.

f B. A. STOWE.

ELECTRIC ARG LAMP.

APPLICATION FILED -MAY 19. 1904.

[./VVENTOR UNITED STATES Patented January 3, 1905.

PATENT OFFICE.

BERNARD A. STOWE, OE CLEVELAND, OHIO, ASSIGNOR TO THE JANDUS ELECTRIC COMPANY, CLEVELAND, OHIO.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 778,915, dated January 3, 1905.

" Application filed May 19, 1904. semi No. 208,681.

.Q all whom, t mfc/y concern:

Be it known that I, BERNARD A. STowE, a resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Electric-Arc Lamps; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use 1o the same.

My invention relates to improvements in electric-arc lamps, and more particularly to a casing therefor, one object of the invention beingl to constructa casing for an electric-arc t5 lamp in such manner that during its process of manufacture the amount of internal or molecular strain in the metal will be reduced to a minimum.

A further object is to so construct the caszo ing that it shall comprise aminimum number of separate pieces.

A further object is to provide simple and efficient means for securing the casing' in position as to eectually prevent vibration,

2 5 and consequent noise between contacting parts, and at the same time permit the casing to be lowered bodily for exposingthe internal mechanism of the lamp.

With these objects in view the invention consists in certain novel features of construction and combinations and arrangements of parts, as hereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure l 3 5 is a. vertical cross-section showing a lamp'- casing embodying my invention. Fig. 2 is a horizontal cross-section'.

The main shell or body l of the lamp-casing consists of a single piece of sheet metal, which is corrugated between special corrugating-rolls, said corrugations being confined to the intermediate portion of the sheet. The operation of corrugating in this manner results in producing a cylindrical shell, inasmuch as the corrugations do not extend the full width of the plate. The metal in the intermediate portion of the plate is crimped and the stock gathered, so as to cause the sheet to assume a cylindrical shape, the length of the uncorrugated portions determining' the 5o circumference of the enlarged portions of the shell and the depth of the corrugations determining the circumference, and consequently the diameter, of the corrugated or intermediate portion of the shell. The depths of the corrugations are graduated at the ends of the main corrugations, so as to produce a gradual change in the diameter intermediate between the small and large diameters of the shell. The enlarged lower portion of the shell is subse- O quentl y crimped, so as to decrease the diameter at the lower end of the edge of the shell, producing thereby a turning in of the shell, which is utilized in the completed casings as a shield or screen 2 for preventing the ingress of water 6 5 through the Ventilating-holes 3 in a cast-iron ring 4, which constitutes an important member of the casing. The overlapping edges of the cylindrical shell are then secured by rivets, soldered or otherwise, and annular grooves or cor- 7 O rugations 5, rolled in the enlarged upper portion of the casing for the purpose of strengtheuing the same. A cap or hood 6 is disposed over the upper enlarged end of the shell and provided with a peripheral flange 7, preferably 7 5 curved transversely. rlhis curved flange projects outwardly from the shell and acts as a water-shed and also to preclude an entrance of dust, rain, and dirt into the casing through the Ventilating-holes 8. The lower enlarged por- 8o tion ofthe casing is provided with an annular groove 9, which engages the cast-iron ring 4 and secured thereto by warping the shell to said cast-iron ring just previous to riveting or soldering the shell. The cast-iron ring 4 8 5 is provided with the Ventilating-holes 3 and supports from its inner periphery a plain cylindrical shell 1l. The method of securing the shell 1I to the cast-iron ring is as follows: The shell l1 primarily is rolled into cylin- 9o drical shape and the edges secured by the welllnown form of lock-seam. An annular bead 12 is then rolled on the shell at a distance from the upper edge greater than the thickness of the cast-iron ring. The shell is then 9 5 inserted into the ring, seated against the annular bead l2, and the stock projecting above the cast-iron ring swaged or turned over, and

the two parts thereby secured together. rlhe shell 11 has secured to its lower end, by means of rivets or otherwise, a shallow stamping 13, of sheet metal, to which the outer globe-supporting device 14- is attached, the shallow stamping serving as a seat for the upper endV of the globe. The globe-supporting' device 14 comprises notched brackets 21 for the reception of bails 22 of the globe-holder 23. The globe-holder consists of a band of wire having' eyes 24 at its ends for the passage of a bolt 25 or other clamping device, and at diametrieally opposite points said band is made with loops 26, with which the bails 22 have hinged connection. Theglobe-holder embraces the neck of the globe, and when the bails 22 are made to engag'e the notched brackets the mouth of the globe will be held iirmly against its seat.

By constructing the casing as above dcscribed no part of the shell is drawn, as the word applies in the art of working' sheet metal. The change in molecular construction is therefore reduced to a minimum and the life of the metal prolonged, even under the most destructive atmospheric conditions. The corrugations and the two or more diameters obtained by this method furthermore strengthen the shell very materially. The lower shell, which is supported from the inner periphery of the cast-iron ring, is devoid of the molecular strains incident to a drawn shell, and the stamping attached thereto being shallow possesses but slight susceptibility to atmospheric conditions.

With arc-lamps as heretofore constructed for use on alternating-current circuits much annoyance has been occasioned by the noise, owing' to the considerable amount of the vibration emanating in the magnets, the alternating' reversals of magnetism set up therein producing a vibration which is transmitted throughout the entire structure of the lamp. rlhe presence of any two parts of the lamp structure or casing, or both, associated in such manner as to permit of a relative movement or vibration of one to the other results in noise which renders the lamp objectionable. To effectually overcome this objection, I propose to secure the easing removably in place by means which will now be explained. The floor-plate 15 of the lamp (which is supported by the central tube 16 of the lamp) is provided with an annular raised portion 17, integral therewith and presenting an inclined surface facing outwardly and which constitutes a surface of revolution of a truncated cone. r1`wo bosses 18 are provided at diametrically opposite points and project from the upper surface of the iron ring et. These bosses are drilled and threaded radially and carry two screws 19, which project radially through and from the casing. The outer ends of these screws are provided with roughened heads 2O for convenience 1n operating the same. The screws 19 are located in such position relative to the case that when the latter is raised to its normal seat within the lamp-hood 6 they will be in such position as to engage the inclined surface forming a part of the floor-plate and which when screwed in results in forcing the case upwardly with considerable pressure against its seat in the hood, and thus preventing relative movement between the casing and the parts of the lamp structure with which it may be in contact. To remove the casing, it is simply necessary to unscrew the two screws a sufiicient distance to permit their ends to disengage the inclined surface and the projecting ledge of the floorplate casting.

The lamp will be adapted to be suspended from a suitable support, as is common in the art of electric-arc lamps, and for this purpose any suitable suspending device may be attached to the head 6.

The .small number of individual pieces employed in the construction of the casing in proportion to its size and pleasing contour is a feature of no small importance. Fundamentally the casing comprises the hood, the main or cylindrical shell, the cast-iron ring, the small cylindrical portion, and the shallow stamping attached thereto.` l'Vith thc exception of the hood all parts are permanently and securely attached to each other, thereby constituting', in so far as its manipulations or removal from the lamp is concerned, a single and one-piece member, and, furthermore, its removal reveals the entire internal structure of the lamp. This casing, with the outer globe attached thereto, is removable from the lamp.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A lamp-casing having a permanentlyclosed peripheral wall, a portion of said wall below its upper end `made contracted in diameter with vertical corrugations, the upper enlarged portion of the casing having' circmnferential corrugations and the lower enlarged portion having an annular inwardly-projecting portion.

2. A lamp-casing comprising a shell having its intermediate portion contracted with vertical corrugations, a ringsecured in the lower enlarged part of the shell, a supplemental shell or sleeve secured at its upper end in said ring and a shallow metal stamping secured to the lower end of said supplemental shell or sleeve.

3. A lamp-casing comprisinga hood, a iioorplate and a rigid connecting device between said hood and floor, of a vertically-movable shell having' Ventilating-holes near its top, a curved flange projecting from the hood and overhanging said Ventilating-holes, means for forcingI the shell against the hood and globesupporting means carried by said shell.

f1. ln a lamp-casing, the combination with a hood, a floor and a rigid connecting' device be- IOO TIO

tween the hood and Hoor, of a vertically-movable shell.l and devices carried by the shell and cooperating with the lamp-floor for forcing the upper end of said shell against the hood.

5. In a lamp-casing, the combination with a hood, a lamp-floor having a beveled projection on its upper face, a ring secured in said shell, and screws mounted on said ring and engaging said beveled projection on the lampiioor.

6. In a lamp-casing, the combination with a shell having a contracted portion provided with vertical corrugations, said shell also having an enlarged portion below the contracted portion and having an internal annular groove, of a metal ring disposed in said groove, a supplemental shell inserted into said ring and having a groove to receive the same and a shallow metal stamping secured to the lower end of said supplemental shell.

7. The combination with a hood, a floor and a rigid connection between said hood and ioor, of a vertically-movable shell having a closed peripheral wall, means for securing said shell in place and globe-holding devices carried by and removable with said shell.

8. The combination with a hood, a loor and a rigid device connecting said hood and Hoor,

of a vertically-movable shell, means for securing said shell in place, a ring secured in the lower portion of said shell, a supplemental shell secured to and depending from said ring a shallow metal stamping secured to said supplemental shell, and a globe-holder mounted on said shallow stamping.

9. The combination with a lamp-frame, of a casing having a permanently-closed peripheral wall, removably7 attached to said frame and normally inclosing the internal structure, notched plates permanently secured to the lower end of the casing, a device to encircle the upper end of the globe and means for connecting said device to the notched plates.

l0. rIhe combination, of a hood, a casing, notched plates at the lower end of the casing, a globe-hold er, and bails attached to said globeholder and adapted to engage said notched plates.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

BERNARD A. STOWE.

I/Vitnesses:

J.`J. ANGEL, HENRY J. VoG'r. 

